scholarly journals Assessment of a 18F-Phenylboronic Acid Radiotracer for Imaging Boron in Maize

2020 ◽  
Vol 21 (3) ◽  
pp. 976 ◽  
Author(s):  
Alexandra B. Housh ◽  
Michaela S. Matthes ◽  
Amber Gerheart ◽  
Stacy L. Wilder ◽  
Kun-Eek Kil ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Lateral Roots ◽  
Phenylboronic Acid ◽  
Primary Root ◽  
Tissue Level ◽  
Root Tip ◽  
Dependent Manner ◽  
Micronutrient Deficiencies ◽  
Maize Roots ◽  
Dose Dependent

Boron (B) is an essential plant micronutrient. Deficiencies of B have drastic consequences on plant development leading to crop yield losses and reductions in root and shoot growth. Understanding the molecular and cellular consequences of B deficiency is challenging, partly because of the limited availability of B imaging techniques. In this report we demonstrate the efficacy of using 4-fluorophenylboronic acid (FPBA) as a B imaging agent, which is a derivative of the B deficiency mimic phenylboronic acid (PBA). We show that radioactively labelled [18F]FPBA (t½=110 m) accumulates at the root tip, the root elongation zone and at lateral root initiation sites in maize roots, and also translocates to the shoot where it accumulates along the leaf edges. Treatment of maize seedlings using FPBA and PBA causes a shortened primary root phenotype with absence of lateral roots in a dose-dependent manner. The primary root defects can be partially rescued by the addition of boric acid indicating that PBA can be used to induce B deficiency in maize and that radioactively labelled FPBA can be used to image sites of B demand on a tissue level.

scholarly journals Nitric oxide effect on root architecture development in Malus seedlings

2011 ◽  
Vol 57 (No. 9) ◽  
pp. 418-422 ◽  
Author(s):  
H.J. Gao ◽  
H.Q. Yang
Keyword(s):  
Nitric Oxide ◽  
Root Architecture ◽  
Lateral Roots ◽  
Primary Root ◽  
Root System Architecture ◽  
Dependent Manner ◽  
Lateral Root Primordia ◽  
Architecture Development ◽  
Two Peaks ◽  
Dose Dependent

 The time-dependent production of nitric oxide (NO) in roots induced by indole-3-butyric acid (IBA) and the effect of sodium nitroprusside (SNP) on root architecture development were investigated, using Malus hupehensis Rehd. seedlings. Following IBA application, a very rapid increase in NO formation and a subsequent second wave of NO burst was observed, which was related to the induction of lateral roots (LRs) and the organogenesis of lateral root primordia (LRP), respectively. The first NO burst was correlated with the second and the two peaks of NO burst induced by IBA were totally abolished by 3,3’,4’,5,7-pentahydroxyflavone (quercetin). Exogenous NO promoted the emergence and elongation of LR and inhibited the elongation of primary root (PR) in a dose-dependent manner: low concentrations of SNP promoted both the amounts and the elongation of LR but inhibited the elongation of LR and PR at higher concentrations. It was concluded that (i) the rapid production of NO induced by IBA was correlated with the IBA-induced initiation of LR; (ii) quercetin inhibition of IBA-induced LR formation was correlated with the quercetin inhibition of IBA-induced NO biosynthesis, and (iii) exogenous NO affects the development of root system architecture in a dose-dependent manner.

Corrigendum - Factors which affects the growth of grain legumes on a solonized brown soil. I. Genotypic responses to soil physical factors

1991 ◽  
Vol 42 (1) ◽  
pp. 95
Author(s):  
BJ Atwell
Keyword(s):  
Root Growth ◽  
Water Status ◽  
Lateral Roots ◽  
Primary Root ◽  
Grain Legumes ◽  
Root Tip ◽  
Physical Factors ◽  
Brown Soil ◽  
Penetrometer Resistance ◽  
System L

Lupins (Lupinus angustifolius cvv. Yandee and 75A-258 and L. pilosus cv. P. 20957) and pea (Pisum sativum cv. Dundale) were grown in the field for 43 days on a solonized brown soil. Shoots of L. pilosus and peas grew most rapidly, while L. angustifolius cv. 75A-258 developed a relatively large root system. L. angustifolius cv. Yandee, a commercial lupin cultivar, was poorly adapted; shoot growth was restricted and roots ceased growing 36 days after sowing. The soil factors responsible for these widely differing responses were investigated. Once primary roots of L. angustifolius were 20-30 cm deep, root extension was slow or arrested. Indeed, primary root apices of Yandee were often necrotic in the soil below 20 cm. In contrast, roots proliferated rapidly in the surface 20 cm of the soil, particularly in 7SA-258, suggesting that factors in the deeper soil layers restricted root growth most severely. The vigorous growth of lateral roots of 75A-258 was reflected in a 2.6 fold greater total root length than for Yandee 43 days after sowing. Soil physical properties were not considered a likely explanation for these observations; soil water status and porosity were always favourable for root growth and root sections indicated that no cortical degradation, typical of O2 deficient roots, had occurred. Penetrometer resistance and root tip osmotic pressures suggested that poor root growth could not be ascribed simply to soil mechanical properties. The results suggest, by inference, that soil chemical factors could underlie the phenotypic responses observed.

scholarly journals Heterogeneous phosphate supply influences maize lateral root proliferation by regulating auxin redistribution

2019 ◽  
Vol 125 (1) ◽  
pp. 119-130 ◽  
Author(s):  
Xin Wang ◽  
Jingjing Feng ◽  
Philip J White ◽  
Jianbo Shen ◽  
Lingyun Cheng
Keyword(s):  
Lateral Root ◽  
Lateral Roots ◽  
Root Tip ◽  
Root Proliferation ◽  
Rich Media ◽  
Maize Roots ◽  
Auxin Redistribution ◽  
Naphthylphthalamic Acid ◽  
Auxin Transporter

Abstract Background and Aims Roots take up phosphorus (P) as inorganic phosphate (Pi). Enhanced root proliferation in Pi-rich patches enables plants to capture the unevenly distributed Pi, but the underlying control of root proliferation remains largely unknown. Here, the role of auxin in this response was investigated in maize (Zea mays). Methods A split-root, hydroponics system was employed to investigate root responses to Pi supply, with one (heterogeneous) or both (homogeneous) sides receiving 0 or 500 μm Pi. Key results Maize roots proliferated in Pi-rich media, particularly with heterogeneous Pi supply. The second-order lateral root number was 3-fold greater in roots of plants receiving a heterogeneous Pi supply than in roots of plants with a homogeneous Pi supply. Root proliferation in a heterogeneous Pi supply was inhibited by the auxin transporter inhibitor 1-N-naphthylphthalamic acid (NPA). The proliferation of lateral roots was accompanied by an enhanced auxin response in the apical meristem and vascular tissues at the root tip, as demonstrated in a DR5::RFP marker line. Conclusions It is concluded that the response of maize root morphology to a heterogeneous Pi supply is modulated by local signals of Pi availability and systemic signals of plant P nutritional status, and is mediated by auxin redistribution.

Factors which affects the growth of grain legumes on a solonized brown soil. I. Genotypic responses to soil physical factors

1991 ◽  
Vol 42 (1) ◽  
pp. 95
Author(s):  
BJ Atwell
Keyword(s):  
Root Growth ◽  
Water Status ◽  
Lateral Roots ◽  
Primary Root ◽  
Grain Legumes ◽  
Root Tip ◽  
Physical Factors ◽  
Brown Soil ◽  
Penetrometer Resistance ◽  
System L

Lupins (Lupinus angustifolius cvv. Yandee and 75A-258 and L. pilosus cv. P. 20957) and pea (Pisum sativum cv. Dundale) were grown in the field for 43 days on a solonized brown soil. Shoots of L. pilosus and peas grew most rapidly, while L. angustifolius cv. 75A-258 developed a relatively large root system. L. angustifolius cv. Yandee, a commercial lupin cultivar, was poorly adapted; shoot growth was restricted and roots ceased growing 36 days after sowing. The soil factors responsible for these widely differing responses were investigated. Once primary roots of L. angustifolius were 20-30 cm deep, root extension was slow or arrested. Indeed, primary root apices of Yandee were often necrotic in the soil below 20 cm. In contrast, roots proliferated rapidly in the surface 20 cm of the soil, particularly in 7SA-258, suggesting that factors in the deeper soil layers restricted root growth most severely. The vigorous growth of lateral roots of 75A-258 was reflected in a 2.6 fold greater total root length than for Yandee 43 days after sowing. Soil physical properties were not considered a likely explanation for these observations; soil water status and porosity were always favourable for root growth and root sections indicated that no cortical degradation, typical of O2 deficient roots, had occurred. Penetrometer resistance and root tip osmotic pressures suggested that poor root growth could not be ascribed simply to soil mechanical properties. The results suggest, by inference, that soil chemical factors could underlie the phenotypic responses observed.

Application of Phytohormones to Pea Roots After Removal of the Apex: Effect on Lateral Root Production

1979 ◽  
Vol 6 (2) ◽  
pp. 195 ◽  
Author(s):  
PB Goodwin ◽  
SC Morris
Keyword(s):  
Lateral Root ◽  
Lateral Roots ◽  
Primary Root ◽  
Root Production ◽  
Root Tip ◽  
Naphthaleneacetic Acid ◽  
Root Initiation ◽  
Lateral Root Initiation ◽  
Lateral Bud ◽  
Bud Growth

Removal of 2 mm of the primary root tip of Pisum sativum caused a complete halt to primary root elongation, but did not alter the total number of laterals formed. The auxins indole-3-acetic acid and 1-naphthaleneacetic acid, when applied to the stump in a lanolin emulsion, increased the number of lateral roots. High levels of abscisic acid and low levels of the cytokinins N6-benzylaminopurine and N6-(γ, γ-dimethylallylamino)purine, and of the gibberellins GA3 and GA7, resulted in decreased lateral root production. Kinetin was without effect. There appears to be an inverse relationship between auxins and cytokinins in root/shoot growth coordination. Auxins, which are produced in the shoot tip, inhibit lateral bud growth but promote lateral root initiation. Cytokinins, which are produced in the root tip, inhibit lateral root initiation, but promote lateral stem growth.

Nitrate and glutamate sensing by plant roots

2005 ◽  
Vol 33 (1) ◽  
pp. 283-286 ◽  
Author(s):  
S. Filleur ◽  
P. Walch-Liu ◽  
Y. Gan ◽  
B.G. Forde
Keyword(s):  
Root Growth ◽  
Lateral Root ◽  
Lateral Roots ◽  
Primary Root ◽  
Root Tip ◽  
Root Tips ◽  
Environmental Signals ◽  
Specific Effects ◽  
Large Numbers ◽  
Low Concentrations

The architecture of a root system plays a major role in determining how efficiently a plant can capture water and nutrients from the soil. Growth occurs at the root tips and the process of exploring the soil volume depends on the behaviour of large numbers of individual root tips at different orders of branching. Each root tip is equipped with a battery of sensory mechanisms that enable it to respond to a range of environmental signals, including nutrients, water potential, light, gravity and touch. We have previously identified a MADS (MCM1, agamous, deficiens and SRF) box gene (ANR1) in Arabidopsis thaliana that is involved in modulating the rate of lateral root growth in response to changes in the external NO3− supply. Transgenic plants have been generated in which a constitutively expressed ANR1 protein can be post-translationally activated by treatment with dexamethasone (DEX). When roots of these lines are treated with DEX, lateral root growth is markedly stimulated but there is no effect on primary root growth, suggesting that one or more components of the regulatory pathway that operate in conjunction with ANR1 in lateral roots may be absent in the primary root tip. We have recently observed some very specific effects of low concentrations of glutamate on root growth, resulting in significant changes in root architecture. Experimental evidence suggests that this response involves the sensing of extracellular glutamate by root tip cells. We are currently investigating the possible role of plant ionotropic glutamate receptors in this sensory mechanism.

scholarly journals Brassinolide Increases Potato Root GrowthIn Vitroin a Dose-Dependent Way and Alleviates Salinity Stress

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Yueqing Hu ◽  
Shitou Xia ◽  
Yi Su ◽  
Huiqun Wang ◽  
Weigui Luo ◽  
...  
Keyword(s):  
Salt Stress ◽  
Stress Tolerance ◽  
Root Development ◽  
Root Elongation ◽  
Primary Root ◽  
Root Activity ◽  
Dependent Manner ◽  
Potato Root ◽  
Dose Dependent

Brassinosteroids (BRs) are steroidal phytohormones that regulate various physiological processes, such as root development and stress tolerance. In the present study, we showed that brassinolide (BL) affects potato rootin vitrogrowth in a dose-dependent manner. Low BL concentrations (0.1 and 0.01 μg/L) promoted root elongation and lateral root development, whereas high BL concentrations (1–100 μg/L) inhibited root elongation. There was a significant (P<0.05) positive correlation between root activity and BL concentrations within a range from 0.01 to 100 μg/L, with the peak activity of 8.238 mg TTC·g−1FW·h−1at a BL concentration of 100 μg/L. Furthermore, plants treated with 50 μg/L BL showed enhanced salt stress tolerance throughin vitrogrowth. Under this scenario, BL treatment enhanced the proline content and antioxidant enzymes’ (superoxide dismutase, peroxidase, and catalase) activity and reduced malondialdehyde content in potato shoots. Application of BL maintain K+and Na+homeostasis by improving tissue K+/Na+ratio. Therefore, we suggested that the effects of BL on root development from stem fragments explants as well as on primary root development are dose-dependent and that BL application alleviates salt stress on potato by improving root activity, root/shoot ratio, and antioxidative capacity in shoots and maintaining K+/Na+homeostasis in potato shoots and roots.

scholarly journals Genotoxic and antigenotoxic potential of the Lagenandra toxicaria Dalz. rhizome methanol extract using Allium cepa assay.

2021 ◽  
Author(s):  
AKARSHA B ◽  
KRISHNAKUMAR GULIMANE
Keyword(s):  
Allium Cepa ◽  
Methanol Extract ◽  
Histochemical Staining ◽  
Biochemical Changes ◽  
Root Tip ◽  
Dna Integrity ◽  
Dependent Manner ◽  
Dose Dependent ◽  
Higher Doses

Abstract This study is the first ever approach to evaluate the possible genotoxic effect of the Lagenandra toxicaria rhizome methanol extract and its antigenotoxic potency against 3% H2O2 induced genetic damage on Allium cepa root tip model. The assay revealed a significant decrease in mitotic index (MI) and an increase in the percentage of clastogenicity in a time and dose-dependent manner in the roots exposed to Lagenandra toxicaria extract at 0.2 mg/ml, 0.5 mg/ml, 1 mg/ml, 5 mg/ml and 10 mg/ml concentration for 1, 2 and 4hour. The ultra structures of cell surface and biochemical changes of the cells were assessed in four hour treated roots using Field emission scanning electron microscopy (FESEM) and Fourier-transform infrared spectroscopy (FTIR). The higher dose of 10 mg/ml treated roots showed an evident morphological as well as biochemical changes compared to the control. The agarose gel electrophoresis showed the loss of DNA integrity in the roots that were treated with 10 mg/ml extract for four hours, where as the control showed comparatively intact DNA bands. The in situ histochemical staining by Schiff’s reagent and nitroblueterasolium (NBT) confirmed the increased lipid peroxidation and free radical generation in four hour treated samples. Subsequently, the possible antigenotoxic potential of the plant extract was explored at its lower doses using H2O2 standard assays. The H2O2 treatment induced nuclear lesions in 93.45 ± 2.33% cells and it was seen to be reduced significantly (50.99 ±7.59 % and 37.13 ± 2.66 %) after the treatment with lower concentration of 0.01 mg/ml and 0.02 mg/ml extract respectively. This suggest that the Lagenandra toxicaria rhizome methanol extract acts as antigenotoxic agent at lower doses but at higher doses the extract induces clastogenic effects and thus acts like a janus-faced compound.

scholarly journals Genetic Damage Induced by a Food Coloring Dye (Sunset Yellow) on Meristematic Cells ofBrassica campestrisL.

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Kshama Dwivedi ◽  
Girjesh Kumar
Keyword(s):  
Azo Dye ◽  
Root Tip ◽  
Dependent Manner ◽  
Sunset Yellow ◽  
Forward Movement ◽  
Control Sets ◽  
Tip Cells ◽  
Dose Dependent ◽  
Root Tip Cells ◽  
Partial Genome

We have performed the present piece of work to evaluate the effect of synthetic food coloring azo dye (sunset yellow) on actively dividing root tip cells ofBrassica campestrisL. Three doses of azo dye were administered for the treatment of actively dividing root tip cells, namely, 1%, 3%, and 5%, for 6-hour duration along with control. Mitotic analysis clearly revealed the azo dye induced endpoint deviation like reduction in the frequency of normal divisions in a dose dependent manner. Mitotic divisions in the control sets were found to be perfectly normal while dose based reduction in MI was registered in the treated sets. Azo dye has induced several chromosomal aberrations (genotoxic effect) at various stages of cell cycle such as stickiness of chromosomes, micronuclei formation, precocious migration of chromosome, unorientation, forward movement of chromosome, laggards, and chromatin bridge. Among all, stickiness of chromosomes was present in the highest frequency followed by partial genome elimination as micronuclei. The present study suggests that extensive use of synthetic dye should be forbidden due to genotoxic and cytotoxic impacts on living cells. Thus, there is an urgent need to assess potential hazardous effects of these dyes on other test systems like human and nonhuman biota for better scrutiny.

scholarly journals GENOTOXIC AND ANTIGENOTOXIC POTENTIAL OF THE LAGENANDRA TOXICARIA DALZ. RHIZOME METHANOL EXTRACT USING ALLIUM CEPA ASSAY

2021 ◽  
pp. 82-90
Author(s):  
AKARSHA B ◽  
KRISHNAKUMAR G
Keyword(s):  
Allium Cepa ◽  
Methanol Extract ◽  
Histochemical Staining ◽  
Root Tip ◽  
Dna Integrity ◽  
Dependent Manner ◽  
Soxhlet Apparatus ◽  
Dose Dependent ◽  
Higher Doses

Objective: The study is to evaluate the possible genotoxic and antigenotoxic potential of Lagenandra toxicaria rhizome methanol extract using Allium cepa root tip assay. Methods: The rhizome methanol extract was prepared using Soxhlet apparatus. The A. cepa roots were treated with various concentrations of the extract at different time points and stained with aceto-orcein. The mitotic index (MI) was calculated. Results: A significant decrease in MI and increase in the percentage of clastogenicity was observed in a time- and dose-dependent manner in the roots treated with the extract at 0.2 mg/ml, 0.5 mg/ml, 1 mg/ml, 5 mg/ml, and 10 mg/ml concentration for 1, 2, and 4 h. The field emission scanning electron microscopy and Fourier-transform infrared spectroscopy revealed evident morphological and biochemical changes at 10 mg/ml treatment when compared to control for 4 h. The agarose gel electrophoresis showed loss of DNA integrity at 10 mg/ml extract for 4 h. In situ histochemical staining by Schiff’s reagent and nitroblue tetrazolium confirmed the increased lipid peroxidation and free radical generation at 4 h treatment. Subsequently, the possible antigenotoxic potential of the plant extract was explored using H2O2 standard assays. The increased percentage of H2O2 induced nuclear lesions was reduced significantly after the modulatory treatment with extract. Conclusion: The L. toxicaria rhizome methanol extract acts as an antigenotoxic agent at lower doses and at higher doses the extract induces clastogenic effects. Further studies are needed to unravel the active component in the extract that mediates the observed phenomenon in the current study.

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